小编Som*_*mus的帖子

我只是SQL的初学者,但我遇到了这个恼人的错误.SQL遇到此脚本的WHERE子句的问题:

SELECT
  ITEM_ID, ITEM_PRICE, DISCOUNT_AMOUNT, QUANTITY, 
  (ITEM_PRICE*QUANTITY) AS price_total, 
  (DISCOUNT_AMOUNT*QUANTITY) AS discount_total, 
  ((ITEM_PRICE-DISCOUNT_AMOUNT)*QUANTITY) AS item_total
FROM ORDER_ITEMS
WHERE item_total > 500
ORDER BY item_total;

我收到此错误:

Error starting at line : 1 in command -
SELECT 
  ITEM_ID, ITEM_PRICE, DISCOUNT_AMOUNT, QUANTITY,  
  (ITEM_PRICE*QUANTITY) AS price_total,  
  (DISCOUNT_AMOUNT*QUANTITY) AS discount_total,  
  ((ITEM_PRICE-DISCOUNT_AMOUNT)*QUANTITY) AS item_total 
FROM ORDER_ITEMS 
WHERE item_total > 500 
ORDER BY item_total DESC;
Error at Command Line : 7 Column : 7
Error report -
SQL Error: ORA-00904: "ITEM_TOTAL": invalid identifier
00904. 00000 -  "%s: …